Windowbox Poly-Pro Flower Box Liner - 36 inch - BLACK Keep your flower boxes lasting season after season Use liners inside of wooden planters or wire hangers Limit rot and rusting caused by water damage Liners consist of traditional, raised-panel plastic and include knockout plugs for drainage Choose from four sizes: 18"L x 8"W x 5.25"H, 24"L x 8"W x 5.25"H, 30"L x 8"W x 5.25"H, or 36"L x 8"W x 5.25"H